Summer might be winding down, but Warner Bros. would like to remind moviegoers that there's plenty more to look forward to this year with several new stills (see below), the star of which is the one we've placed above, showing Sylvester Stallone, Robert De Niro and comedian Kevin Hart bickering in their boxing comeback movie Grudge Match.

Previously, the only pictorial evidence of this film was a TwitPic with a bloody and bruised De Niro and Stallone posing for a snap mid-bout. A trailer also leaked, but was swiftly taken down.

The director is Peter Segal, who previously brought us Anger Management, Naked Gun 33⅓: The Final Insult and and 50 First Dates. The plot of the Grudge Match - which may remind some of Rocky Balboa - goes like this:

Back in the '80s, two Pittsburgh fighters, Billy “The Kid” McDonnen (De Niro) and Henry “Razor” Sharp (Stallone), had a fierce boxing rivalry. The Kid had beaten Razor, Razor had beaten The Kid, but in 1983, just before their decisive third match, Razor suddenly announced his retirement with no explanation.

Thirty years later, boxing promoter Dante Slate Jr. (Hart) makes them an offer: re-enter the ring and settle the score. But before that happens, whilst they're both in mo-cap suits for a boxing computer game, their fued spills over into a slap-filled fight in an office, which is picked up on a mobile phone and goes viral on YouTube. Now their rematch is a must-see HBO event, and their biggest task is to survive the training (which may or may not include punching some hanging meat).